Overactive thyroid or taking supplemental thyroid hormone dramatically increases the risk for macular degeneration, an eye disease that robs individuals of their central vision used for reading, driving, etc. There is no effective cure or therapy for the main form of the disease, though dietary supplements (AREDS Formula) weakly slow down its progression.

Indigenous peoples, living near naked, outdoor lives, under the sun reach 25(OH)D around this point so whether we want to enable naturally vitamin d breastmilk, prevent cancer, reduce diabetes incidence, delay the onset of dementia, maintain optimal immune function, be in the optimum position to resolve inflammation to do any or all of these functions we need a reserve of bioavailable cholecalciferol readily accessible.

If doing so also reduces the pressure on the parathyroid then why may it work overtime 24/7?

Pease don't forget selenium is very helpful with thyroid and para thyroid. Macular degeneration cause is oxidisation along with liver spots. Your natural antioxidant is glutathione but it has only one life time but selenium can reactivate it to work again